Fabrication of ZnO nanostructured sensor by co-precipitation technique for NO2 gas detection
Objectives: To detect the harmful NO2 gas in an environment by using ZnO nanostructure.
Methodology: ZnO nanostructure has been synthesized by a simple co-precipitation method. The synthesized sample was annealed at 500ºC for 3 hours. The structural, morphological, elemental composition, functional groups, optical and electrical properties were investigated by using XRD, FESEM, HRTEM, EDX, XPS, FTIR and UV-Visible techniques. The structural analysis of the ZnO sensor specifies that they are hexagonal wurtzite structure. Findings: The gas sensing abilities of ZnO nanostructure were studied various oxidizing and reducing gases such as Cl2, H2S, NO2 and SO2. The ZnO nanostructure was extremely selective towards NO2 gas with an extreme response of 232% at 100 ppm concentration and the working temperature 200ºC. The ZnO sensor shows good stability and reproducibility towards NO2 gas. The sensing mechanism of the ZnO sensor towards air and NO2 gas was proposed. The present work offers a novel route for effectively making of nanostructured ZnO sensor for destructive NO2 gas detection.